Field of the Invention
The present invention relates to an exposure control apparatus and method, a storage medium, and an image pickup apparatus, and in particular to an exposure control apparatus and method that controls exposure using an image signal output from an image pickup element, which photoelectrically converts a subject image, a storage medium, and an image pickup apparatus.
Description of the Related Art
In general, some image pickup apparatuses such as digital cameras control exposure with a so-called backlight judgment made. For example, some image pickup apparatuses detect an area of an intermediate luminance region between two luminance levels supplied from an external device, and an average luminance level in the intermediate luminance region, and detects a backlight state by judging a backlight level based on the area and the average luminance level (see Japanese Laid-Open Patent Publication (Kokai) No. H09-266549, for example).
Further, there are camera systems which, when providing image pickup control including exposure control, provide image pickup control appropriate to shooting scenes in conjunction with detection information on images taken by another camera. Here, when one's own camera and another camera are placed in an area where shooting is desired, image pickup is controlled with emphasis placed on one of the cameras which is able to stably obtain detection information such as brightness and color temperature of shooting scenes (see Japanese Laid-Open Patent Publication (Kokai) No. 2011-254339, for example).
In the image pickup apparatus described in Japanese Laid-Open Patent Publication (Kokai) No. H09-266549, it is difficult to reliably detect a backlight state because a distinction is made between a subject region and a background region according to luminances between two levels supplied from an external device. This is because when the two levels supplied from the external device are not appropriate values due to a reflectivity of a subject, a color of a background, and so on, the subject region cannot be properly set.
Further, according to Japanese Laid-Open Patent Publication (Kokai) No. 2011-254339, when one's own camera and another camera are placed in an area where shooting is desired, image pickup is controlled with emphasis placed on detection information from the camera with higher stability, but because the plurality of cameras makes observations in the same direction, their detection information is likely to have equal stability. Thus, for example, in the case of making a backlight judgment, judgment accuracy does not greatly differ according to whether the judgment is made based on detection information from only one of the cameras or based on detection information from both of the cameras.